Incidence algebras and Möbius inversion form a cornerstone of combinatorics. It has important applications in many areas of
mathematics. Beyond the original applications in number theory (see Hardy and Wright [1]}) and group theory
([2]} and [3]}), one can cite applictions in probability theory [4]} and algebraic topology [5]}, and it is also closely related to Hopf-algebraic renormalisation [6]} in quantum field theory.
